1. Field of the Invention
The present invention relates to the field of telecommunications. More particularly, the present invention relates to routing toll free calls placed over a dedicated access line (DAL).
2. Background Information
A dedicated access line (DAL) service provides a subscriber with a direct line to a long distance carrier's switch, bypassing the local telephone company network and reducing costs. Subscribers to a DAL service typically would like to place all of their long distance calls over the DAL in order to prevent increasing their local trunk groups to accommodate this toll free traffic.
Some long distance networks, however, do not permit DAL subscribers to dial toll free numbers over the DAL. The limitation is caused by the inability of these long distance networks to perform toll free database look ups, which are required to associate the dialed toll free number with an actual routing number. For example, networks employing the Nortel DMS 250 long distance tandem switching systems may not be configured to query a national service management system (SMS). Consequently, the DAL subscribers must place their toll free calls via the local telephone company.
The present invention overcomes the problems associated with the prior art, as described below.